Gas desuperheating apparatus



y 1968 A. A. LUOMA ETAL GAS DESUPERHEATING APPARATUS Filed June 11, 1965 Na 8 2. v llv I:

0+. ow Nu i ones AARNE A. LUOMA ALBERT F. HANSCHKE $0M M. M;

United States Patent 3,385,572 GAS DESUPERHEATING APPARATUS Aarne A. Luoma and Albert F. Hanschke, Wellsville,

N.Y., assignors to Worthington Corporation, Harrison, N.J., a corporation of Delaware Filed June 11, 1965, Ser. No. 463,243 4 Claims. (Cl. 261-23) ABSTRACT OF THE DISCLOSURE An apparatus for preventing superheating of throttled gases by means of a desuperheating spray system which includes dual cam means interconnected for serial operation, with said first cam means operating throttle valve means disposed within a gas flow passageway, which passageway communicates with a cooling fluid conduit means downstream of the throttle valve means and said second cam means, in cycle with the first cam means, actuates a valve means within said cooling fluid conduit means only when said first cam means causes said throttle valve means to throttle the flow of gas flowing in said passageway.

This invention relates to a new and improved apparatus for the prevention of the superheating of gases and, more particularly, to a desuperheating spray system, and manner of operation thereof, for preventin the superheating of gases upon the throttling thereof.

Experience has shown that the throttling of certain gases results in the superheating thereof and attendant undesirable formation of a sticky, black, tar-like deposit of generally insoluble characteristics. This has proven to be particularly true in the throttling of sewage gases which may be utilized in the running of power generation turbines, and comprise approximately 38% by weight of steam and 62% by weight of organic gases with traces of organic oil mixed therein. In such applications, the throttling of these gases, as through a valve, during the transfer thereof from a point of collection to the inlet of a power generation turbine, has been determined to result in the superheating of the said gases and attend-ant, undesirable formation of the generally insoluble deposits as discussed above. It is, therefore, an object of our invention to provide a new and improved apparatus for the prevention of the superheatiug of gases and attendant formation thereby of undesirable deposits during the throttling of the said gases.

Another object of our invention is the provision of ap paratus as above which are particularly adaptable to the throttling of gases through a valve, and are automatically operable in response to the operational condition of the said valve, i.e. whether or not the valve is throttling the gases passing therethrough.

Another object of our invention is the provision of an apparatus as above which embody the supply of a suitable cooling liquid, as for example water, to gases concurrently with the throttling thereof to prevent the superheating of the said gases.

Another object of our invention is the provision of apparatus as above wherein the supply of a cooling liquid to gases being throttled through a valve is adjusted automatically in accordance with the extent to which the said gases are being throttled whereby, the amount of the said cooling liquid supplied is greatest when the need therefor is greatest.

A further object of our invention is the provision of apparatus as above which are of particularly uncomplicated, inexpensive and durable design and construction, whereby the costs of fabrication, installation and operation thereof are minimized, and long periods of satisfactory, maintenance free operation thereof are assured.

3,385,572 Patented May 28, 1968 ice The above and other objects and advantages of our invention are believed made clear by the following detailed description thereof taken in conjunction with the accompanying drawings wherein:

The drawing is a schematic illustration of a desuperheating system constructed in accordance with the teachings of our invention.

Referring now to the drawing, a plurality of generally identical governor valves are indicated generally "at 10, 12, 14, 16 and 18, respectively, with each of said governor valves comprising a valve casing 20 with a gas flow passage 22 extending therethrough, a valve member 24 positioned in said passage and adapted to close the same, a valve stem 26 attached to and controlling the position of the said valve member in the said gas flow passage, a valve operating arm 28 pivotally supported as indicated at 30 and attached to the said valve stem as indicated at 32, and a biasing spring 34 cooperatively associated with the said valve operating arm for biasing the valve to the closed position thereof.

In a typical installation, the governor valves 10, 12, 14, 16 and 18 may be utilized to control the flow of sewage gases of the nature described above from non-illustrated points of collection thereof to a plurality of symmetrically oriented sets of inlet nozzles of a non-illustrated, power recovery turbine, through the respective gas flow passages 22 of the said governor valves, to control the operation of the said turbine. Tothis effect, each of the valve members 24 of the respective governor valves is movable between closed and design lift positions thereof in its associated valve casing, and it is only when the said valve member is in a position thereof intermediate said closed or design lift positions that the corresponding governor valve will exert .a throttling effect upon the gases flowing therethrough of sufficient extent to give rise to the superheating of the said gases.

A governor valve camshaft 36 is rotatably supported as shown adjacent the said overnor valves in any convenient manner, and governor valve ocntrol earns 40, 42, 44, 46 and 48 are spacedly positioned as shown on the said camshaft and rotatable therewith.

A cam follower roller 50' is rotatably positioned on the free extremity of each of the governor valve operating arms and is cooperatively associated as shown with the adjacent governor valve control cam, whereby may be readily understood the manner in which the operational condition of governor valve 10 is controlled by governor valve control cam 40, governor valve 12 by governor valve control cam 42, governor valve 14 by governor valve control cam 44, governor valve 16 by governor valve control cam 56, and governor valve 18 by governor valve control cam 48, respectively.

Spray nozzles 50, 52, 54, 56 and 58, respectively, project as shown into the gas flow passage interiors of the respective casings 20 of the governor valves 10 12, 14, 16 and 18, with said spray nozzles being connected in turn as shown to a cooling liquid supply conduit 59 by branch conduits 60, 62, 64, 66 and 68 extending therebetween.

A source of a suitable cooling liquid under suitable pressure, as for example water at 1800 psi, is indicated at 69 and connected as shown to the liquid supply conduit 59, whereby cooling water at high pressure is available at the respective spray nozzles.

Solenoid operated valves 70, 72, 74, 76 and 78, respectively, are connected as shown in the respective branch conduits 60, 62, 64, 66 and 68, and may thus be understood to control the flow of coolin water therethrough to the said spray nozzles. A check valve 80 is connected as shown in liquid supply conduit 59 downstream of the source 69 of pressurized cooling liquid, and manually operable, gate valves 82, 84-, 86, 88, 90, 92, 94, 96, 98

and 100, respectively connected both upstream and downstream as shown of the respective solenoid controlled valves 70 72, 74, 76 and 78 in the respective branch conduits 6t), 62, 64, 66 and 68.

A solenoid operated valve control assembly is generally indicated at 102 and comprises a housing 104 into which a solenoid operated valve camshaft 106 projects as shown. The said solenoid operated valve camshaft is connected in any convenient manner, as for example by a universal joint 38, to the adjacent extremity of the governor valve camshaft 36 so as to be rotatable therewith.

Solenoid operated valve control cams 110, 112, 114, 116 and 118, respectively, are spacedly positioned as shown on the said solenoid operated valve camshaft and are rotatable therewith. Limit switches 120, 122, 124, 126 and 128, respectively, are positioned as shown within the said housing adjacent the said solenoid operated valve control cams, and comprise actuator arms 130, 132, 134, 136 and 138, respectively, which extend as shown into cooperative association with the respective solenoid valve control cams. The said limit switches are arranged to be in the respective otf" positions thereof when the respective switch actuator arms are not depressed by the respective solenoid operated valve control cams, and to be in the respective on positions thereof when the said arms are so depressed. Thus may be readily understood whereby rotation of the said solenoid operated valve control cams in the counter-clockwise direction will result in the successive movement of the said limit switches to the on positions thereof.

The respective limit switches 120, 122, 124, 126 and 128 are electrically connected as shown to the respective solenoid operated valves 72, 74, 76, 78 and 80 by conductors 140, 142, 144, 146 and 148 connected therebetween. A test light as indicated at 150 in conductor 148 is connected in each of the said conductors for purposes described in detail hereinbelow.

The said solenoid operated valves are arranged to be in the closed positions thereof when the valve operating solenoids are not energized, and to be in the open positions thereof when the said solenoids are energized. Thus may be readily understood whereby depression of a limit switch actuator arm, as for example actuator arm 130, by the rotation of solenoid operated valve control cam 100, will result in movement of limit switch 120 from the 01f position thereof to the on position thereof, the opening of the solenoid operated valve 70 associated therewtih, the supply of water to the spray nozzle 50 controlled by the said solenoid operated valve through branch conduit 60, and the spray of water into the gas flow passage 22 of the governor valve in which the said spray nozzle is positioned the same sequence of operation is of course true for the remaining switch actuator arms, solenoid operated valve control cams, limit switches, solenoid operated valves, spray nozzles and governor valves, respectively, as should be obvious.

Superheating of the gases which may leak along the respective stems 26 of the governor valves 10, 12, 14, 16 and 18, and attendant undesirable formation of deposits thereon also presents a problem to the proper operation of the said governor valves. To this effect, spaced, soft type packings as indicated 150 and 152 for the governor valve 10, rather than the more conventional metallic bushing type packings, are utilized around the said valve stems where the same pass through the respective valve casings 20. Flow passages 154 and 156 are formed as shown in the said valve casings and extend therethrough into fluid flow communication with the space between the said soft type packings. Non-illustrated retaining means are of course provided to retain the said packings around the said valve stems.

A water supply conduit 158, and a water return conduit 160 are provided, with the former being connected to flow passage 154 by branch conduit 162 extending therebetween, and the latter being connected to flow passage 156 by branch conduit 164 extending therebetween.

Cooling water under relatively low pressure, as for example 10 psi, is continuously communicated to water supply conduit 158 from any convenient, non-illustrated source thereof and flows therefrom to fiow passage 154 through branch conduit 162 connected therebetween, from the said fiow passage to and through the space between the soft type packings and 152 into contact with the valve stem 26, and therefrom to the water return conduit 169 through flow passage 156 and branch conduit 164 connected therebetween. Thus may be readily understood whereby cooling water is continuously circulated through contact with the valve stem 26 between the said soft type packings to prevent the superheating of gases which may leak therealong past the soft type packing 152 from the interior of the valve casing 20. For convenience of illustration, the above-described valve stem water supply means are depicted only for governor valve 10, it being understood however that the said valve stem water supply means are also incorporated in the same manner in governor valves 12, 14, 16 and 18, respectively.

In a typical application of the desuperheating system of our invention, as for example in the prevention of gas superheating and attendant undesirable formation of a generally insoluble deposit on the respective valve stems 26, the valve members 24 and the walls of the gas flow passages 22 of the governor valves 10, 12, 14, 16 and 18 during the use of the said governor valves to control the flow of sewage gases to a plurality of symmetrically oriented sets of inlet nozzles of a power generation turbine, the said system is operated in the following manner.

Initially, the configurations and relative orientations of the respective governor valve control earns 40, 42, 44, 46 and 48 are chosen to provide for the desired gas flow controlling operation of the governor valves. Once these factors have been established, the respective configurations and relative orientations of the solenoid operated valve control cams 110, 112, 114, 116 and 118 are then chosen in accordance therewith to provide for the superheating prevention operation of each of the cooling water spray nozzles at all times when the governor valve associated therewith is throttling the fiow of gas therethrough, i.e. whenever the said governor valve is in a position thereof intermediate the closed and design lift positions.

Thus, assuming clockwise rotation of governor valve cam shaft 36, a governor valve opening order of 14, 16, 12, 10 and 18 with a 35 governor valve camshaft rotation between the commencement of the opening of each succeeding governor valve, and of governor valve camshaft rotation being sufi'icient to bring all of the governor valves to the design lift positions thereof, the said governor and solenoid operated valve control cams will be shaped and relatively oriented as depicted in the drawing.

Operation of the respective solenoid operated valves 70, 72, 74, 76 and 78 is then tested by clockwise rotation of governor valve camshaft 36 and observation of each of the test lights 150 to insure that the said lights are on whenever the governor control valve associated therewith is in a position thereof intermediate the closed and design lift positions thereof, thus indicating that cooling water would be supplied to each of the governor control valves during such periods due to the energization of the solenoid operated valve associated therewith. In this manner, any necessary adjustment of the respective actuator arms of the limit switches 120, 122, 124, 126 and 128, relative to the solenoid operated valve control cams, may be effected.

Once it has been determined that the entire system is properly adjusted throughout to provide for operation thereof in the desired manner, cooling water supply conduits 59 and 158 are connected to the respective water supplies therefor, the respective gate valves 82, 84, 86, 88, 90, 92, 94, 96, 98 and 100 opened, and the respective governor valves connected between a source of sewage gas and the plurality of symmetrically oriented sets of power generation turbine inlet nozzles as discussed above. Thus, the continuous flow of cooling water from supply conduit 158 past the respective valve stems 26 between the spaced, soft type packings 150 and 152 of each of the governor valves will be commenced.

Once clockwise rotation of governor valve camshaft 36 is begun, governor valve control cam 44 will act upon valve operating arm 28 to commence the opening of governor valve 14 and resultant throttling thereby of the sewage gas flowing through the flow passage 22 of the said valve. Concurrently therewith, solenoid operated valve control cam 114 will act upon actuator arm 134 of limit switch 124 to close the latter and energize solenoid valve 74 through conductor 144 connected therebetween. Thus, solenoid operated valve 74 will be opened and cooling water supplied, through water supply conduit 59 and branch conduit 64, to the spray nozzle 54 and therefrom into the sewage gas flowing through the governor valve 14 to cool the said gas and prevent the superheating thereof.

Operation continues in this manner until governor valve camshaft 36 has been rotated approximately 35 in the clockwise direction, at which point the valve member 24 of the governor valve 14 will have assumed the design lift position thereof and will no longer have any significant throttling effect upon the sewage gas flowing therethrough. Thus, solenoid operated valve control cam 114 is designed to release actuator arm 134 of limit switch 124 after 35 rotation of the said cam, whereby the solenoid operated valve 74 will be deenergized and reclosed to discontinue the now unnecessary Supply of cooling water to the spray nozzle 54. Governor valve 14 remains open, however, with sewage gas flowing therethrough under substantially unthrottled conditions.

Concurrently therewith, governor valve control cam 46 will commence the opening of governor valve 16, and solenoid operated valve control cam 116 will close limit switch 126 to open solenoid operated valve 76, whereby cooling water will be sprayed from spray nozzle 56 into the sewage gas flowing, under throttled conditions, through governor valve 16, thus preventing the superheating of the said gas.

Continued clockwise rotation of governor valve camshaft 36 through another 35 will result in valve member 24 of governor valve 16 having assumed the design lift position thereof to no longer have any significant throttling effect upon the sewage gas flowing therethrough. Thus solenoid operated valve control cam 116 will release actuator arm 136 of limit switch 126 to discontinue the now unnecessary supply of cooling water to governor valve 16, with the said governor valve remaining open, however, in the manner of governor valve 14.

Concurrently therewith, governor valve control cam 42 will commence the opening of governor valve 12, and solenoid operated valve control cam 112 will close limit switch 122 to commence the supply the supply of cooling water to the said governor valve through spray nozzle 52.

Continued clockwise rotation of governor valve camshaft 36 through another 35 will result in the valve member 24 of governor valve 12 assuming the design lift position thereof, the discontinuance of the supply of cooling water to the said governor valve through spray nozzle 52, the commencement of the opening of governor valve and the supply of cooling water to the sewage gas flowing therethrough, under throttled conditions, through spray nozzle 50. Governor valve 12 remains open, however, in the manner of governor valves 14 and 16.

Further clockwise rotation of governor valve camshaft 36 through another will result in the discontinuance of the supply of cooling water through spray nozzle to governor valve 10, and the commencement of the opening of governor valve 18 and attendant supply of cooling water thereto through spray nozzle 58, with governor 6 valve 10 remaining open in the manner of governor valves 14, 16 and 12.

Continued clockwise rotation of governor valve camshaft 36 through an additional 35 will result in the valve member 24 of governor valve 18 having assumed the design lift position thereof, with attendant discontinuance of the supply of cooling water thereto through spray nozzle 58 due, of course, to the release of actuator arm 138 of limit switch 128 by solenoid operated valve control cam 118, and the attendant reclosing of solenoid valve 78.

At this point, all of the governor valves are open but are not exerting any significant throttling effect upon the sewage gases flowing therethrough, whereby may be readily appreciated that the discontinuance of the now unnecessary supply of cooling water through the respective spray nozzles to the said gases, results in significant economies in the operation of the said valves through the conservation of the supply of the highly pressurized cooling water. Too, although the supply of low pressure coling water from supply conduit 158 to the valve stems 26 is continuous, it may be noted that the said low pressure cooling water is recirculated, with only negligible losses thereof, and that the low pressure thereof makes any such negligible losses even less significant from a system operation economy point of view.

It is believed apparent from the above description of the depicted governor valve desuperheating system that reverse rotation of the governor valve camshaft 36, i.e. in the counter-clockwise direction, from any but the initial position of the said camshaft, will result in reverse operation of the system. Thus, for example, if it is assumed that the said camshaft is rotated 30 in the counter-clockwise direction after having first been rotated 45 in the clockwise direction, governor valve 16 will be reclosed and the supply of cooling water thereto through spray nozzle 56 discontinued, while valve member 24 of governor valve 14 will be returned to a position thereof intermediate the closed and design lift positions, whereby the governor valve 14 will again throttle the sewage gases flowing therethrough and the supply of cooling water thereto through the spray nozzle 54 will be resumed accordingly.

Although the supply of cooling water to the valve stems 26 from supply conduit 158 has been disclosed as of a continuous nature for reasons discussed above, it is within the scope of this invention to control such supply, as for example through solenoid operated valves in the nature of solenoid operated valves 70, 72, 74, 76 and 78, from the limit switches 120, 122,124, 126 and 128 in accordance with the operational condition of each of the governor valves.

The supply of cooling water through each of the spray nozzles 50, 52, 54, 56 and 58 to each of the governor valves 10, 12, 14, 16 and 18 adjusts automatically in accordance with the extent to which the said governor valve is throttling the gases flowing therethrough. Thus, for example, in the case of governor valve 14, the said governor valve exerts its maximum throttling effect upon the gases flowing therethrough just after the valve has commenced to open. At this point, the pressure in the gas flow passage 22 just below the valve member 24 is substantially equal to the first stage turbine inlet pressure, which is of course below the gas inlet pressure. Thus, the pressure against which the constant pressure cooling water must discharge from the spray nozzle 54 is at its minimum whereby the amount of cooling water discharge from the said spray nozzle will be at its maximum to provide for the maximum desuperheating effect at the point of greatest need, i.e., the point at which the said governor valve is exerting its maximum throttling effect on the gases flowing therethrough.

Conversely, with the governor valve 14 operating under almost design lift conditions, the said governor valve will be exerting its minimum throttling effect upon the gases flowing therethrough. At this point, the pressure in the gas flow passage 22 just below the valve member 24 is substantially equal to the inlet pressure of the gases, which is of course higher than the turbine inlet pressure. Thus the pressure against which the constant pressure cooling water must discharge from the spray nozzle 54 is at its maximum, whereby the amount of cooling water discharged from the said spray nozzle will be at its minimum to provide for minimum desuperheating effect at the point of least need, i.e., the point at which the said governor valve is exerting its minimum throttling effect on the gases flowing therethrough. Thus may be readily appreciated whereby the new and improved apparatus of our invention prevent the superheating of gases being throttled by the automatically selective introduction of a cooling liquid thereto only when needed, and in quantities commensurate with the extent of the need therefor.

It is to be understood that the respective governor valves 10, 12, 14, 16 and 18 are not open to the maximum possible extents thereof when the said valves reach design lift conditions. Thus, for example, with governor valve 16 at the design lift condition after 35 clockwise rotation of governor valve control cam 46, further clockwise rotation of the said control cam will result in further opening of the said governor valve. This further opening of the said governor valve is of no particular consequence to the operation of the desuperheating system of the invention, however, because throttling of the gases passing through the said valve is substantially discontinued once the latter has reached the design lift condition thereof.

The extent of movement of the valve member 24 from the closed to design lift position thereof may vary depending upon the application to which the governor valve is being put. In the application of the hereindisclosed preferred embodiment, the said extent will equal approximately one quarter of the diameter of the valve seat, whereby a valve seat diameter of one inch will result in one quarter inch movement of the valve member therefrom to bring the latter to the design lift position thereof.

What is claimed is:

1. In an apparatus for preventing the superheating of gases:

(a) a valve casing with a gas flow passage extending therethrough;

(b) a bore in the valve casing;

(c) a valve member disposed in the gas flow passage and movable therein between a closed and design lift position so as to throttle a gas flowing through the gas flow passage as the valve member is lifted off its seat;

(d) a valve stem extending from the valve member into the bore in the valve casing;

(e) spaced first and second soft type bushings disposed around the valve stem within the bore with these bushings disposed to form a space through which the valve stem extends;

(f) means for circulating a cooling fluid through the space between the first and second soft type bushings in contact with the valve stem;

(g) means for supplying a cooling fluid to the valve casing gas flow passage at a location in the gas flow of cooling fluid with increased throttling and decreasing the quantity of cooling fluid with decreased throttling.

2. In an apparatus for preventing the superheating of gases comprising:

(a) a plurality of parallel valve casings with a gas flow passage extending through each;

(b) a valve member disposed within each valve casing obstructing the gas flow passage therein 'with each valve member movable sequentially between a closed and design lift position so that gases flowing through the gas flow passage will be throttled to a varying extent as the valve member is raised from the closed to the design lift positions;

(c) control means for controlling operation of said valve member including a plurality of primary cam means connected with each valve member to move each valve member in sequence between the closed and design lift positions;

(d) a cooling fluid supply means;

(e) spray nozzle means extending into each valve casing on the downstream side of the gas flow passage with the spray nozzles connected to the cooling fluid supply means;

(f) said control means further including a plurality of secondary cam means connected with the plurality of primary cam means, means operable with the secondary cam means to control the interval when cooling fluid is supplied to the spray nozzles so that cooling fluid is supplied only during throttling;

(g) control valve means connected with the plurality of secondary cam means to supply cooling fluid to the spray nozzles upon command from the secondary cam means;

(h) said control means including means to vary the quantity of cooling fluid supplied to the gas stream within the valve casing during throttling, so that a greater quantity of fluid is supplied with increased throttling and a lesser quantity of fluid is supplied with decreased throttling.

3. In apparatus as in claim 2 wherein, said means for varying the said quantity of said cooling fluid comprise, a source of said cooling fluid at substantially constant pressure connected to said spray nozzles through said control valve means.

4. In apparatus as in claim 3 further comprising, a bore formed in each of said valve casings, valve stem means extending from each of said valve members into said bores, spaced, first and second soft type bushings disposed around said valve stem means in each of said bores to form spaces therebetween through which said valve stem means extend, and cooling fluid supply means for circulating a cooling fluid through each of said spaces into contact with said valve stem means which extend therethrough.

References Cited UNITED STATES PATENTS 1,322,406 11/1919 Cable. 1,832,652 11/1931 Peebles. 2,254,472 9/1941 Dahl. 2,611,240 9/1952 Patterson. 2,972,229 2/ 1961 Chandler et al. 3,026,889 3/1962 Bryant 60-l04 X 3,207,492 7/1965 Zikesch 261-46 RONALD R. WEAVER, Primary Examiner. 

